From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2] x86/HVM: change the flags cpu context field to uint64_t Date: Mon, 18 Jan 2016 15:24:06 +0000 Message-ID: <569D0396.2060207@citrix.com> References: <569CFAEE.3050805@citrix.com> <1453129771-78737-1-git-send-email-roger.pau@citrix.com> <569D10F002000078000C8169@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aLBfK-0006k6-U1 for xen-devel@lists.xenproject.org; Mon, 18 Jan 2016 15:24:23 +0000 In-Reply-To: <569D10F002000078000C8169@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Roger Pau Monne Cc: xen-devel@lists.xenproject.org, Ian Jackson , Ian Campbell List-Id: xen-devel@lists.xenproject.org On 18/01/16 15:21, Jan Beulich wrote: >>>> On 18.01.16 at 16:09, wrote: >> --- a/xen/include/public/arch-x86/hvm/save.h >> +++ b/xen/include/public/arch-x86/hvm/save.h >> @@ -161,8 +161,8 @@ struct hvm_hw_cpu { >> uint32_t error_code; >> >> #define _XEN_X86_FPU_INITIALISED 0 >> -#define XEN_X86_FPU_INITIALISED (1U<<_XEN_X86_FPU_INITIALISED) >> - uint32_t flags; >> +#define XEN_X86_FPU_INITIALISED (1UL<<_XEN_X86_FPU_INITIALISED) >> + uint64_t flags; >> }; > How is the UL going to make this safe for a 32-bit consumer? > Makes me think that, other than just said in reply to v1, it'll > indeed be better to have a separate field (with a separate > zero-check)... The (undesirable imo) alternative being to use > 1L instead. I am happy either way. My R-b stands. ~Andrew